I have TomatoUSB shibby build with Guest wireless setup. Everything works fine. I've setup a separate bride on 192.168.1.1-51 and they are getting their address assigned properly. They are also unable to see the computers from the main wireless network.

My issue is that I have a USB drive attached to my router that I use for my backup. Right now the guest network can just look at \\192.168.1.1\ to list and access the USB drive.

Is there something I can do to prevent guest access to my USB drive that doesn't involve password protecting the share?